Former prime minister Kevin Rudd has launched a scathing attack on Australia's current political landscape, saying the Liberal and Labor parties are populated by "serious nut jobs" and "factional thugs".

"I think our approach to that is the only rational approach given our geographical circumstances in the world," Rudd continued.

While his comments on offshore detention were not entirely barnstorming, it was his seemingly off-the-cuff musings on the current state of Australian politics that will garner the most attention.

Asked about the first weeks of Malcolm Turnbull's reign as PM, Rudd conceded "objectively speaking, you have to say [Turnbull] had a good start".

Rudd said that while he did not contact deposed PM Tony Abbott after he was rolled in a leadership ballot in September, he did sympathise with Abbott -- with Rudd having been knifed in similar circumstances in 2010 by then-deputy Julia Gillard.

"When you encounter a very public personal political and political loss, look, everyone is a human being. So therefore you do feel for people under those circumstances," Rudd said.

"But as we know, it's a rough and tumble business. Mind you, Malcolm has his challenges. He has to deal with the lunar right of his party and there are serious nut jobs there, we all know that," he continued, to laughter from the audience.

"Just as, you know, when I was Prime Minister and there's Bill [Shorten] today dealing with factional thugs from certain trade unions who make life difficult. We all have our problems."

"Some of those people on the lunar right, [nutjob] is a generous term in the case of some."